Hand operated switch



E. L. FEIL HAND OPERATED SWITCH Oct, 11, 1960 Filed Jan. 18 1957' 5Sheets-Sheet 1 INVENTOR.

Oct. 11,1960 E. L. FEILI 5 HAND OPERATED swn'cn Filed Jan. 18, 1957 *5Sheets-Sheet a g I 7 l 0 s as Z .JJF

INVENTOR.'

Oct, 11, 1960 E. L. FElL 2,955,135

HAND OPERATED SWITCH Filed Jan. 18, 1 95? 5 Sheets-Sheet 5 IN V EN TOR.44 m 1- United States Patent HAND OPERATED SWITCH Edward L. Feil,Euclid, Ohio, assignor to The Clark Controller Company, Cleveland, Ohio,a corporation of Ohio This invention relates generally to manuallyoperable electric switches.

While the invention may be used generally as a circuit maker andbreaker, it has particular application as a socalled manual starter forstarting and stopping an electric motor.

A type of manual motor starter is known comprising switchcontacts in thecircuit of the motor, which can be manually moved to closed position;and which have a snap mechanism that can be tripped manually to causethe contacts to go to open position with quick break or snap movement;and which mechanism will be tripped by an electric overload in the motorcircuit.

The present invention relates to manual starters of this type.

The actual invention is that set forth in the appended claims.

The embodiment of the invention fully described hereinafter, comprises,in general the following.

The switch as a whole is detachably mounted upon the interior bottomwall of a sheet metal box-like casing, and a cover on the casingentirely encloses the switch except for an operating handle accessiblethrough a handle open.- ing in the cover.

The switch has stationary and movable contacts, and a snap mechanism;and the snap mechanism is operable by the handle to disengage thecontacts or engage them with snap action; and the mechanism is operatedautomatically by a thermal device to trip or disengage the contacts withsnap action upon the occurrence of a current overload through theengaged contacts; and the mechanism is operable by the handle to resetthe mechanism after automatically tripping.

The handle thus has four positions and these are indicated by legends onthe handle visible through the handle opening in the casing.

The switch proper comprises a generally flat base mounted on the casingbottom wall as referred to; and the snap mechanism is permanentlymounted as a unit on the base; and a housing, generally of bowl formdownwardly open as viewed in the drawing, is attached to the .basecovering the mechanism.

A pair of transversely spaced arms, connecting the handle to themechanism, pass upwardly through spaced .apertures in the bowl bottom.

In its preferred form, as illustrated herein, there are three parallelcurrent paths through the switch, each controlled by contacts, whichadapt the switch as a starter for a three phase motor.

The parts constituting each of the said three paths comprise a pair ofstationary contacts and the heating coil of a thermal tripping device;both in series befor all three paths, are in straight lines and theterminals are mounted on the outside of the housing bowl bottom ice 2and exposed for ready access upon removing the casing cover.

There are movable bridging contacts, for bridging the pairs ofstationary contacts, disposed outwardly of, or above, the housing bowlbottom, and a reciprocator connecting them with the mechanism, passesthrough another aperture in the bowl bottom.

Thermal devices are mounted on the underside of the bowl bottom, one foreach heating coil.

Upon removing the casing cover, the base with all of the above describedparts thereon can readily be detached from the casing bottom wall andremoved as a unit, for inspection.

The handle is readily detachable; and upon removing the handle and thebridging contacts, the bowl housing, by virtue of said apertures, may beremoved from the base, leaving the mechanism mounted on the base andexposed for inspection.

Production assembly in the first instance is facilitated by reversal ofthese removing operations.

In the aforesaid arrangement, the mechanism and thermal devices aredisposed under the said three conducting paths and thereby do not add tothe length between the terminals of the paths, and by the economy ofspace thus effected, there is made room for thermal devices for allthree of the current paths which is not possible in prior switches ofthis class without unduly increasing the length of the switch as awhole. The handle by being detachable also makes possible a switch ofoverall minimum length.

A connection is provided by which the one mechanism can be tripped, oncurrent overload, by any one of the three thermal devices alone, or byany two, or all three of them concurrently.

The bowl housing is molded from insulating material and has arc chamberwalls surrounding the contacts on three sides at their make and breakzones; and the reciprocator carrying the bridging contacts is moldedfrom insulating material and comprises a transverse bar portion carryingall three of the bridging contacts and formed to provide a fourthchamber wall; whereby the contact make and break zones are eachsurrounded by arc chamber walls on all four sides.

The said transverse reciprocator is provided with finlike barriers,between the pairs of bridging contacts which prevents flash-over fromany current path to another.

The detachable connection for the handle comprises a pin going throughthe handle and through apertures in the said handle arms on each side ofit, which open into slots. The handle is normally prevented fromrotating on the pin by projections on the handle overlapping portions ofthe arms. The pin is shiftable manually axially against the force of aspring and thereupon disposes small diameter portions of the pinopposite to the slots, whereby the pin can be withdrawn from theapertures through the slots and the handle freed therefrom, and theprojections freed from the arms, to permit the handle to be removed.

The pin has a finger mounted on an end thereof at a side of the handle,which is movable laterally of the bandle with axial movement of the pin,and then rotatable with the pin.

Normally, an end of the finger is disposed in a recess in the side ofthe handle and is then in .an out of use position.

When the pin is moved axially as described, the finger end is withdrawnthereby from the recess and the finger is then manually rotatabledownwardly to a position in which its end is disposed behind a shoulderon the housing bowl.

This can only be done when the handle is in the oil 3 position and itlocks the handle against accidental or unintended movement to the on"position.

The aforesaid snap action mechanism is in general of the over-centerspring type; and the parts are economically made as flat sheet metalstampings, mounted on pins that are supported in the side walls or legsof a U-shape metal frame mounted, preferably permanently, on the saidbase.

Movement over and beyond dead center condition occurs when the handleand handle arms are moved from off to on position or vice versa; andprovision is made by which, if the parts should tend to stick or forother reason fail to go over center, movement of the handle arms willcause the arms to engage the parts and force them to go over andbeyond'dead center.

The said three thermal devices are alike and each of a known solderedshaft type, and comprising a finger that is snapped upwardly by a'springwhen the solder is melted by heat in the heating coil; and is reset byforcing the finger downward.

Provision is made by which the handle arms when moved, to resetposition, after tripping, as mentioned, will forcibly reset the fingersof any one or more of the devices that have snapped upwardly.

The snap mechanism comprises a latch that moves upon occurrence of anoverload and a toggle connected to the over-center spring action. Oneend of the toggle is connected to a fulcrum carried by the latch. Whenthe latch is moved because of an overload, the latch carried fulcrum isshifted to cause the snap mechanism to operate and open the contacts.

The embodiment illustrated and described herein is particularly adaptedas a starter for a three phase motor, by having three current pathstherethrough to be made and broken; but it is to be understood that theembodiment may comprise parts to make and break only one or two currentpaths therethrough and used for other purposes; and that while thermaloverload devices are provided in all three of current paths illustratedand described, the overload device in one of the paths, say the middlepath, may if desired, be omitted.

The objects of the invention are to provide a switch having the featuresbriefly described above, singly or in combination.

An embodiment of the invention is fully disclosed in the followingdescription taken in connection with the accompanying drawing, in which:

Figs. 1 and 2, are respectively side elevational and top plan viewsshowing a sheet metal casing in which the switch part of the inventionis enclosed; Fig. 2 showing an opening in the top through which a switchoperating handle projects;

Fig. 3 is a sectional view from the plane 3-3 of Fig. 1, to enlargedscale, full size, showing the switch in top plan;

Fig. 4 is a longitudinal sectional view of the embodiment of Fig. 3 alsofull scale, from the plane 44 ,of Fig. 3; with a switch handle shown inside elevation, and a mounting pin of the handle broken off and in crosssection;

Fig. 5 is a fragmentary sectional view from the plane 5-5 of Fig. 4; andwith bridging contacts of Fig. 4 removed;

Fig. 6 is a fragmentary plan view in the direction of the arrow 6 ofFig. 4, with stationary and bridging contacts of Fig. 4 removed;

Fig. 7 is a fragmentary view of a part of the switch of Fig. 3, but withthe handle of Fig. 3 omitted;

Figs. 8, 9, 10 and 11 are views similar to part of Fig. 4, in somerespects diagrammatic, showing a switch and operating snap mechanismtherefor in different operated positions; and these views may bereferred generally to the plane 8 of Fig. 12;

Fig. 12 is a fragmentary plan view of the mechanism of Fig. 8 from theplane 12 of Fig. 8;

Figs. 13, 14, 15 and 16 are top plan views of a handle as seen throughan opening in the casing of Fig. 2, in the different operated positions,respectively, of Figs. 8, 9,10 and 11;

Fig. 17 is a diagrammatic view, illustrating different angular positionsof the handle corresponding to Figs. 8, 9, 10 and 11;

Fig. 18 is a fragmentary view similar to a part of Fig. 4 illustratingin more detail, a thermal trip device of Fig. 4;

Fig. 19 is a sectional view from the plane 19 of Fig. 18; I

Fig. 20 is a fragmentary view from the plane 2020: of Fig. 18;

Fig. 21 is a side elevational view of a handle and part of a housing;from the plane 2121 of Fig. 3;

Fig. 22 is a view in the direction of the arrow 22 of Fig. 21, with partbroken away and in section;

Fig. 23 is a View similar to Fig. 22 with operable parts for detachingthe handle shown in operated positions;

Fig. 24 is a side elevational view from the plane 2424. of Fig. 23;

Fig. 25 is a view similar to Fig. 21 but with operable.-

parts thereof locking the handle in operated positiom Referring to thedrawing, the switch is shown in hori-- zontal position for convenienceof description, but usually will be used in vertical position.

The switch proper as shown in Figs. 3 and 4 com-- prises a metalplatelike base 33 and an inverted :bowl shaped housing 34 downwardlyopen, formed from in-- sulating material mounted on the base 33 byscrews 35..

The switch proper is enclosed within a casing, shownin Figs. 1 and 2 tosmall scale, comprising an upwardly open box 1 and a downwardly openoverlapping box. cover *2 mounted detachably thereon by slot and screwconnections one of which is shown at 3, Fig. l.

The box cover 2 has a rectangular opening 4 there-- through givingaccess and freedom of movement to a: grip 5 on an operating handle 6, bywhich, as will be: shown later, the handle .can be oscillated back andforth. arcuately around the .aXis of a pin A, Fig. 4, to different.switch operating positions.

The handle 6 has an arcuate coaxial upper surface 7 Fig. 4, and theopening 4 is in a corresponding arcuately formed portion 8 of the casingcover, close to which the surface 7 of the handle is overlappinglydisposed, so that the handle in all positions thereof substantiallycloses the opening 4. As will be described the handle 6 is movable,manually, to an on position to close switch contacts; and to an offposition to open the contacts; and moves automatically to a trippedposition to open the contacts upon the occurrence of current overloadthrough the confacts; and is movable manually to a reset position afterautomatic tripping, to restore the contacts to manual operation.

Legends ON, OFF, TRIPPED and RESET are provided on the surface 7 of thehandle, and come into position to be visible to the operator to indicatethe said respective positions of the switch, as shown in Figs. 13, l4,l5 and 16.

The handle 6 is attached to a pair of spaced handle arms 910, see Figs.4, 8 to 10 and 12, oscillatable on a stationary pin A of a snapmechanism to be described; and the arms go upwardly to the handle fromthe mechanism through slots 211-212 in the bowl housing, see Fig. 7; andthe handle is detachable from the arms by the following constructionwith reference to Figs. 4 and 21 to 25.

The ends of the arms 910 are generally of hook form, being provided withaligned circular perforations 11-12 opening into slots 1314 of smallerwidth than the perforations.

Outwardly of the slots 1314, the arms have fingers 15-. 6.

Under the fingers 15-16 are lower stops 17-18 on the handle.

Above the fingers 15-16, but displaced therefrom to ward the left, asviewed in the drawing, are upper stops 19-20 having grooves 22 receivingthe upper sides of the fingers 15-16.

The underside of the handle 6 is hollowed out to provide opposite spacedribs 23-24.

A handle pin 25 has large diameter portions 26-27 normally incorresponding bores in the ribs, and rotatable and axially slidabletherein; and normally retained in the bores in the retracted axialposition of Fig. 22, by a spring 28 reacting between the rib 24 and acollar 29 on the pin or a split ring attached thereto, and abutting uponthe rib 23.

In this axial position of the pin 25, its large diameter portions 26-27are in the perforations 11-12 of the handle arms, and as indicated inFig. 4, this keeps the handle 6 and its pin 25 from shifting toward theright, as viewed; and keeps the lower stops 17-18 under the fingers15-16 and the stops 19-20 above the fingers, so that the handle 6 cannotrock on the pin 25; and the handle is thus attached to the handle arms9-10.

To detach the handle, the pin 25 is shifted axially, against the springtension to the position of Fig. 23, by pressing manually on a knob 29aon the pin. The pin has small diameter portions 30-31, which upon thusaxially shifting the pin, are moved to positions opposite the slots13-14 as shown in Fig. 23.

The handle and pin may now be moved toward the right, as viewed, thesmall diameter portions of the pin moving in the slots 13-14, and theparts going to the position indicated in Fig. 24, where the smalldiameter portion 31 of the pin is entirely out of the slot 14.

In this position of the handle 6 the lower stops 17-18 are removed fromunder the fingers 15-16, as shown for the Stop 18 of Fig. 24, and aswill be apparent from Fig. 24, the handle may be moved upwardly anddetached from the handle arms 9-10.

Obviously it may be reattached by a reversal of the foregoingoperations.

At this point it may be interjected that the handle arms 9-10 may belocked against their oscillating movements around the fixed pin A, asaforesaid, and this is provided for when the arms are in the offpositions of Figs. 3, 4 and 8 to be described, to prevent accidental orunintended operation of the switch to the on position. This is done asfollows with reference to Figs. 4, 7, 21 to 23 and 25.

In Fig. 7, the handle arms 9-10 are shown as coming up through the bowlhousing 34 through slots 211-212 therein and forwardly thereof is ashoulder 32 on the bowl housing.

The passage of the arms through the housing is indicated in Fig. 4.

In Fig. 4 also is shown the shoulder 32; and in Figs. 21 and 25 theshoulder is reproduced on a fragmentary portion of the housing 34. Thehandle arms are locked as mentioned by'an obstruction on the handlemoved optionally to a position to abut upon this shoulder 32 as follows.

As shown in Figs. 21, 2-2 and 23, a locking bar 36 is secured upon theend of the handle pin 25 opposite the manual knob 29a, and is thereforemovable axially and rotatively with the pin.

The locking bar 36 has a body flange 37, on the end of which is a finger38, which in the normal position of the parts, Figs. 21 and 22, holdsthe bar in an out of use position by being projected into a recess 39 inthe side of the handle 6.

When the pin 25 is moved axially, manually, as described, the -lockingbar 36 moves with it to the position of Fig. 23, which withdraws thefinger 38 from the recess 39 and then the bar 36 can be hingeddownwardly, as viewed, the pin being free to rotate to accommodate thismovement.

The flange 37 overlaps the shoulder 32 and stops the downward hingingmovement as in Fig. 25.

The locking bar 36 also has a flange 40 depending therefrom, the end ofwhich lodges behind the shoulder 32, as in Fig. 25, and this locks thehandle 6 and arms 9-10 against being oscillated toward the right awayfrom the said off position.

Reversal of the foregoing operations will restore the finger 38 into therecess 39, releasing the lock, as is obvious.

Mounted on top of the inverted bowl housing 34 are the parts of threeparallel conducting paths, which adapt the switch for use as a threephase motor starter.

The parts constituting these several paths are alike, and a descriptionof one of them say the middle one will sufiice as shown in Fig. 4 andindicated in Fig. 3.

It comprises a terminal 41 at the left end as viewed, mounted on thehousing by a screw 42 and having a terminal screw 43 thereon for Wireconnection to say a motor;

A stationary contact element 44 having a contact tip 45 thereon, andmounted on the housing by a screw 46;

A thermal device heating coil 47 connected at opposite free ends byscrews 48-49 to the terminal element 41 and the contact element 44;

Another stationary contact element 50 having a contact tip 45A, mountedon the housing by a screw 51, and continuing as a terminal elementhaving a terminal screw 51A thereon for wire connection to, say, supplylines.

The inverted bowl housing has a bowl bottom wall portion 52, and athermal device, generally at 53 depends therefrom being mounted thereonby bolts 54, and, err-- tending upwardly through the wall 52 and coaxialwithin the coil 47 has a thermo-responsive shaft construction 55..

This thermal device is shown in Fig. 18 in more detail. than in Fig. 4,and is shown separately in Fig. 20.

It is generally of known construction as follows.

A stationary tube 56 of the device, has a shaft 57 therein connected atits lower end to a toothed wheel 58, and the shaft is soldered to thetube.

Stationary arms 59-60 extend downwardly from the supporting wall 52 andhave a pin 61 in their lower ends on which is oscillable a trip finger62 by upstanding cars 63 thereof hinged on the pin 61.

An upwardly extending leaf spring 64 is secured to one of the cars 63and at its upper end has a tooth 65 engaged by its resilience with theteeth of the wheel 58.

A spring 66 around the pin 61 reacts on the trip finger 62 and on thearm 60 tending to snap the finger upwardly and rotate the wheel 58 butrestrained from doing so by the solder.

Upon heating the shaft constructiton 55 by an overload value of currentin the coil 47, the solder melts and the Wheel 58 is released and thetrip finger 62 is snapped upwardly by the spring 66 from the normalhorizontal position shown in Figs. 18 and 4, to the dotted line position62A in Fig. 18, and solid line position Fig. 10.

The upper side of the bowl housing is formed to have a chamber 67 seeFigs. 4, 5 and 6, by chamber walls on three sides at 69-70-71; and achamber 68 having like Walls 72, 73 and 74; into which the contactelements 44 and 50 respectively extend, and in which the contact tips 45and 45A are disposed.

These chambers are, as will be apparent, in line with the middleconducting path over the top of the bowl housing here being described;and it may be interjected here that in line with the other twoconducting paths, there are pairs of chambers 75-76 and 77-78 for thecontacts thereof, like the chambers 67-68.

A reciprocator comprising a transverse bar 79 rectangular in crosssection and formed from insulating material Figs. 5 and 6, extendstransversely across the bowl housing, between the inner ends of thechamber walls 72-74 and 69-71 and constitutes a fourth chamber wall foreach of the chambers 6768; and provides alike fourth wall for thechambers 7576 and 77-78.

A metal, movable bridging contact bar 80 rests upon the top of thetransverse bar 79 and has contact tips 81-81A on its underside alignedwith the stationary contact tips 45-45A.

The bridging bar 80 is mounted on a post 82 of oblong rectangular crosssection embedded in the bar 79 and extending through a washer 83 andhaving a head 84 overlapping a washer 83 on the post, and a spring 85around the post reacts between the 'bar 80 and the washer 83.

The assembly of these parts is of known construction. It comprises afirst oblong short rectangular perforation in the washer aligned withthe head 84, but shorter than the head so that the ends of the headoverlap its ends.

To detach the washer 83 it is moved downwardly on the post until itcomes to a neck thereon around which it is rotated ninety degrees; andthe Washer has a long perforation at right angles to the shortperforation which is then directly under the head; and the washer isthen moved upwardly telescoping the long perforation over the head toremove the washer. The long perforation is shown at 86 in Fig. 3.

The washer may be reattached by reversal of the foregoing operation.

The bridging bar 80 is held down on the transverse bar with springpressure as is apparent.

The washer 83 is thus readily removed and the spring 85 and bridgingcontact 80 may then be readily removed.

In operation later to be described the bridging bar 80 is moveddownwardly to engage its tips 8181A with the stationary contact tips4545A and then moves farther holding the contacts in closed conditionunder yieldable spring pressure.

The transverse bar 79 carries three posts and bridging bars like thepost 82 and bridging bar 80 above described, for the said respectivethree conducting paths, and for simplification of the drawing, the postshave been shown in Fig. 6 at 88, 82 and 89 with the bridging barsremoved and in Fig. the posts 88, 82 and 89 and the three bridging bars90, 80 and 91 have been shown with the washers and springs removed.

The transverse bar 79 is preferably molded from insulating material; andbarriers 139 and 140 are formed on it, between each adjacent two of thesets of contacts, extending both upwardly and downwardly and precludethe possibility of flash over from one set of contacts to the other.

Under the bowl housing 34 is a snap mechanism to be described, operatedby oscillation of the handle arms 910 by the handle, which snaps thetransverse bar 79 down and up to engage and disengage the said movableand stationary contacts. The handle arms are described above asoscillatable on a stationary pin A of the mechanism.

The transverse bar 79 has lugs 9293, depending therefrom through anaperture 94 in the housing, Fig. 4, and a pin B of the mechanism isprojected through aligned holes in the lugs, Figs. 4 and 5.

As described, the handle 6 and the bridging bars 90-8091 are readilydetachable. It is an important part of the invention that afterdetaching them and after detaching the housing from the base 33 at thescrews 35, the entire bowl housing 34 and all of the parts mountedthereon as described can be removed as a unit, without disturbing thesnap mechanism, leaving the arms 9--10 and the lugs 92-93 on themechanism pins A and B and exposing the mechanism for inspection; andindependent operation; this removal of the unit being made possible bythe arm slots 211-212 described for Fig. 7 and the lug aperture 94described for Fig. 4.

To give access to the screws 35-35 for this purpose the base 33 as shownin Figs. 3 and 4 is mounted on the bottom casing wall 95 by screws 96-96and 97 in 8 slots 98--98-99 formed so that upon loosening the screws9696 and 97 the base 33 can he slid toward the right as viewed and itsright end raised to clear the screw 97 and then slid further to theright to clear the screws 9696; whereby the base 33 can be removed fromthe casing, and the screws 3535 exposed for access thereto.

The said snap mechanism will now be described, and is shown in the saidoff condition in Figs. 4 and 8; in the on condition in Fig. 9; in theoverload tripped condition in Fig. 10; and in the reset condition inFig. 11, see also Fig. 12.

A metal mechanism frame 100 of U-form comprising a closed end 101 andspaced side legs 102103, see Figs. 4 and 19, has the closed end 101mounted, preferably permanently, on the base 33 by screws 104-104, Fig.4 with the side legs 102103 extending, parallel, upwardly therefrom.

The said horizontal pin A is mounted in aligned holes in the frame legs102--103.

The handle arms 910 are alike flat sheet metal stampings, mounted tooscillate on the pin A and are formed to comprise upwardly extendinghandle portions 105, generally horizontal portions 106, large eyes 107,and extensions 108; the latter connected to and carrying a horizontalpin C projected therethrough.

A pair of alike flat links 109 of the bell crank type stamped from sheetmetal have mid-points mounted on the said pin B and one leg 110 mountedon the pin A, the other leg 111 at an acute angle to the leg 110,carrying a horizontal pin D which, extends through aligned arcuate slots112 in the side legs 102-103 of the frame 100 concentric with the pin A,and upon one end of which, in operation, the pin D is stopped as inFigs. 4, 8, 10 and 11 and on the other end of which it is stopped as inFig. 9.

A latch 113, stamped from fiat sheet metal has an intermediate portionmounted on a stationary horizontal pin E which at its ends is supportedin holes in the side legs 102-103. To the left of the pin E, as viewed,it has an upwardly inclined portion 114 and in its left end is a notch115; and to the right of the pin E it has an upwardly inclined portion116 carrying a short pin F, and beyond the pin F has a hook portion 117and a prong 118 of which, as in Figs. 10, the hook portion may hook overthe pin C, or as in Figs. 8-11 and 4 the prong 118 may engage the top ofthe pin C.

A pair of stamped flat sheet metal links 119119 are mounted at one endon the pin F and at the other end carry a pin G, which goes through theeye 107.

A pair of stamped flat sheet metal links 120-120 are mounted at one endon the pin G and at the other end on the pin D.

A pair of parallel triggers 121121 are mounted at their right ends onthe pin A and are connected together by a generally horizontal web 122,and extend toward the left therefrom, all made from a metal stamping inone piece and bent; the web being under the pin A, Figs. 8 to 1'2 and19.

The right hand edge of the web 122 is disposed so that in operation itmay at times be engaged by the notch 115 of the latch 113.

A pair of tension springs 12-3123 are connected to and between the pinsG and C; and a tension spring 124 is connected to the pin D and hookedover the left end of the trigger web 122 and being below the pin A givescounterclockwise torque to the triggers 121121.

The said frame side legs t102-103 have vertical aligned slots 137138therein.

The aforesaid thermal device 53 is described above for the middle one ofthe said three conducting paths of the switch, and its said trip finger62 thereof extends between the frame side legs 102-103, Figs. 18 and 19.The other two devices for the other two conducting paths, are mounted inthe same way as that described for the device 53 and as indicated inFig. 19 they have trip fingers 125-126 parallel to and at the same levelas to the trip finger 62, beyond opposite sides of the U-frame 100.

A flat transverse trip bar 127 stamped from sheet insulating material,extends through the aligned slots 137- 138 in the frame legs 102-103 andis slidable up and down therein and guided thereby; and has horizontallyaligned notch edges 128-129-130 normally resting upon all of the tripfingers 125, 62 and 12.6 to support the trip bar 127 in the slots, seeFigs. 19' and 18.

The trip bar 127 has feet 131-132 disposed a short distance above thebase 39, Fig. 19, and has a top edge 133 parallel to the trip fingers125-62-126.

Operation of the snap mechanism will now be described.

It will be assumed that the mechanism is in the aforesaid condition ofFigs. 4 and 8.

The springs 123-123 between the pins G and C, being above the pin F onthe latch 113, are pulling on the pin G, tending to rock the links 119clockwise around the pin F. p

The pin G therefore pulls on the links 120 and pin D, and thereby pin Dis held against the right end of the slot 112 as a stop therefor.

The pin D is in the bell crank 109 and holds the bell crank in a stoppedcounterclockwise position around the stationary pin A and thereby holdsthe pin B, and the transverse bar 79 and bridging contact bars 90-80-91of all three conducting paths in elevated position with the switchcontacts open.

The pin G also presses the links 119 upon the pin F by the spring force,but the pin F, on the latch 113 cannot move, because the latch cannotrotate on the stationary pin E, its left end being locked by notch 115engaged with trigger web 122 and the latter being held counterclockwiseby the spring 124.

The links 120 and 119 and pin G thus constitute a bent toggle betweenthe pin D and the pin F on the latch, the pin F acting as a togglefulcrum.

The handle arms 9-10 and handle 6 are thus held in a definitepredetermined off position, which can therefore be correctly indicatedon the handle legends as described. The right end of the arms 9-10cannot move up because the pin C is stopped by the underside of thelever prong 118; and while the pin C is free to be moved downward, doesnot do so because that would lengthen the springs 123-123, and theyresist it.

To operate the switch to the on position, the pin C is moved downward bythe operator, by moving the handle arms 9-10 clockwise around thestationary pin A in Figs. 4 and 8 and the parts snap to the on conditionof Fig. 9 as follows.

The latch 113 remains unmoved as before.

The center line of the pins C-G is moved below the pin F on the latch;and the toggle comprising the links 119-120 straightens out, reacting atthe right end on the pin F as a fulcrum and at the left end moving thepin D to the left end of the slot 112 whereon it is stopped.

The pin D in so moving rocks the bell crank 109 clockwise on thestationary pin A, moving the pin B downwardly, which as will now beunderstood, closes the switch contacts.

This occurs with snap action caused by the springs as soon as their lineof action, between pins G and C goes to overcenter condition passing thepin F.

The extensions 108 of the arms 9-10 go down into contact with the base33 as shown in Fig. 9 and are stopped thereon in a definite positionwhereby the legend on the handle 6 can indicate on position correctly asshown in Fig. 14.

The arms 9-10 remain in the on position of Fig. 9 when the operatorreleases the handle. When the pin C starts to move downward as referredto, the springs 123-123 are lengthened and after they snap the toggle119-120 as referred to they shorten again, and thus resist upwardmovement of the pin C.

When the pin C is moved downward, to cause the line of action betweenpins C and G to pass the pin F, the pin G, due to wear of the parts orto friction, may tend to stick or lag and not snap down to the positionof Fig. 9, and to insure that it will snap down, the eyes 107 in thehandle arms 9-10 have each an edge 134 so disposed as to come intocontact with the pin G and forcibly move it toward or beyond the deadcenter position.

With the switch and mechanism in the on condition of Fig. 9, and withthe switch contacts closed, as will be understood, if an overloadcurrent occurs, say in the middle conducting path of the switch here tobe considered, the thermal device 53, has its trip finger 62 at thatmoment in the position of Figs. 9, l8 and 19 and the top edge 133 of thetrip bar 127, resting on the finger, is slightly below the triggers121-121.

When the overload current actuates the thermal device 53, the tripfinger 62 snaps upwardly as described, to the dotted line position 62Aof Fig. 18 and solid line position Fig. 10; and the mechanism snaps tothe tripped condition of Fig. 10 as follows.

As shown in Fig. 10 the trip finger 62 has elevated the trip bar 127 andits upper edge 133 has rocked the triggers 121 around the stationary pinA against the tension of the spring 124 and has withdrawn the triggerweb 122 from the notch of the latch 113, and freed the latch, from itslocked position of Fig. 9.

Before this, when the parts were in the on condition of Fig. 9, thesprings 123 pulling on the pin G were exerting pressure on the pin Fapplying torque to the latch tending to rotate it clockwise around thestationary pin E.

Now that the latch has been freed, it is so rotated with snap action andgoes to the position of Fig. 10, where it is stopped by the hook portion117 thereof engaging the pin C. i

The pin F carried by the latch thus moves to a position below the lineof spring action between the pins G and C as in Fig. 10.

Then force of the springs 123-123 accordingly moves the pin G toward theright as viewed, to the position of Fig. 10 and the pin G, pulling onthe links pulls the pin D to the right end of the slot 112 upon which itis stopped.

This movement of the pin D rocks the bell crank 109 counterclockwisearound the stationary pin A and elevates the pin B, opening the switchcontacts as will now be understood.

As mentioned, the pin F on the latch is a fulcrum for one end of atoggle comprising the links 120, 119 and the pin G; and the snapmovement of the parts from the on position of Fig. 9 to the trippedposition of Fig. 10 thus results from shifting the position of a togglefulcrum on a latch, which is believed to be a novel principle in theart.

In going to tripped conditions of Fig. 10, the handle arms 9-10 as willbe seen, move counterclockwise to a position between their positions inon and off condition, and because of being stopped by the pin D at theend of the slot 112, will remain in that position, and the position willbe definite so that the legends on the handle will correctly indicatethat thermal trip has occurred, as shown in Fig. 15.

The foregoing describes thermal trip for the trip finger 62 for overloadin the middle conducting path of the switch.

Overload current in the two other paths will similarly snap upwardly thetrip fingers 125-126 of their thermal devices.

As will be seen from Fig. 19 when the trip finger 62 snaps upwardly, thetrip bar 127 will be bodily elevated and elevate its top actuating edge133 for the described purposes. If either of the trip fingers 125 and126 snaps upwardly, but the others do not, the trip bar 127 will beelevated at one end and elevate the corresponding end of the actuatingedge 133, rocking the bar upon the trip fingers that remain unsnapped,and thus tilting the bar. I

The triggers 121-121 above the edge 133 are spaced apart suflicientlyand close enough to the edge 133 so that in the said tilted position ofthe bar it will engage and elevate one or the other of the trip fingersto trip the mechanism as described.

Thus an overload in any one, or any two, or all three of the currentpaths will trip the mechanism and open the switch contacts as described.

To restore the mechanism to normal operating condition after thermaltripping it is reset by the operator from the tripped condition of Fig..to the reset condition of Fig. 11 and then released by the operatorwhereupon it goes to the off condition of Fig. 8.

To do this the handle arms 9-10 are moved counterclockwise as viewed inFig. 10, beyond the described off position thereof.

The arms 9-10 have lower edges, which before tripping are spaced abovethe top edge 133 of the tripping bar 127, as shown in Fig. 4; and whichare engaged by the upper edge 133 of the tripping bar 127 when it movesupwardly upon tripping, see Fig. 10.

The said counterclockwise movement of the handle arms 9-10 around thestationary pin A, to reset the mechanism move these edges downwardly,thereby moving the tripping bar 127 downwardly to the position of Fig.11 and causing the tripping bar to restore downwardly to normal,positions the trip fingers of the thermal devices that caused tripping,as shown in Fig. 11.

The triggers 121 engaged with the top edge 133 of the trip bar 127, tendto remain in contact with the edge 133 and tend to follow the edgedownwardly due to the spring 124 but do not do so for the followingreasons.

The counterclockwise resetting movement of the handle arms 9-10 raisesthe pin C from the position of Fig. 10 to that of Fig. 11 and rocks thelatch 113 counterclockwise around the stationary pin E by the engagementof the pin C with the hook portion 17 and prong 118 of the latch.

The latch on its left end, below the notch 115, has a rounded cammingedge 136 which upon rocking of the latch as just described comes intocontact with the web 122 of the triggers 121, and'in going from theposition of Fig. 10 to that of Fig. 11, it cammingly rotates the web 122and triggers 121 clockwise around the pin A to res-tore the triggers tonormal positions above the top edge 133 of the tripping bar 127, asshown in Fig. 11.

Counterclockwise rotation of the latch 113 as just described is stoppedby engagement with the pin D as shown in Fig. 11 with the notch 115 alittle below the web 122; and stopping the latch also stops theresetting movement of the handle arms 9-10 as will be apparent, so thatthere is no liability that the trip bar 127 will be pushed down too farby the edges 135 or beyond a desired normal position.

The handle arms 9-10 being thus stopped in a definite position, thelegends on the handle indicate reset correctly, as shown in Fig. 16.

When the operator releases the handle arms after resetting, the reactionof the springs 123-123 causes the handle arms 9-10 to settle backclockwise and the latch is thereby caused to settle back clockwise untilthe notch 115 is in locked engagement with the trigger web 122,

and the mechanism is then again in the normal off con-' dition of Fig.8, as indicated in Fig. 13.

It is to be noted that the edges of the circular slots 112 through whichthe pin D extends, are not guides for the pin. The pin D is constrainedto oscillate in a circular are around the stationary pin A independentlyof the slot edges by virtue of the one piece bell crank 109 formed ofthe legs 110-111. Wear on the pin D and slot edges is thus avoided.

The aperture 112 is preferably provided'of circular slot form as 'aconvenient means of providing the rounded 12 pin embracing stops at theends of the slot for the pin D.

In some cases, it will be suflicient to omit the thermal overloadtripping device 53 from one of the conducting lines through the switch;and when this is done, the heating coil 47 can also be omitted and awire substituted therefor between the screws 48 and 49, Fig. 4.

A part of the invention resides in the snap mechanism and its mode ofoperation. Therefore some of the advantages of the invention may be had,with only two or even one of the three conducting paths through thedevice, as described.

Normally, the switch is operated manually between the off and onpositions. Once in the on position, the switch is manually operated tothe off position by the operator moving handle 6 counterclockwise, Fig.9 to Fig. 8. This moves handle arms 9 and 10 counterclockwise around thestationary pin A and the parts snap to the off position of Fig. 8 asfollows.

The latch 113 remains unmoved as before.

The centerline of pins C and G is moved above pin F on latch 113. Thetoggle comprising links 119 and 120 collapses or breaks due to thetension in springs 123-123 and using pin F as a fulcrum at its rightend. By collapsing, the left end of the toggle moves pin D to the rightend of slot 112 Whereon it is stopped.

Pin D by this movement rocks bell crank 109 counterclockwise onstationary pin A to move pin B upwardly, which as hereinbefore describedopens the switch contacts.

This occurs with snap action as soon as the line of action of'pins C andG goes beyond overcenter" condition, passing pin F, because of springs123-123.

Pin C moves counterclockwise until it comes into contact with prong 118of latch 113, whereby its movement is stopped at a definite position.The legend on handle 6 now indicates the off position as shown in Figure13.

When pin C moves upward to cause the line of action between pins C and Gto pass pin F, the parts may tend to stick or resist the movement of pinG due to wear or friction. To insure that pin G does move and themechanism snap, an inside edge of eyes 107 in handle arms 9 and 10 comesinto contact with pin G and forcibly moves it toward and beyond the deadcenter position.

Although I have described my invention with a certain degree ofparticularity, it is to be understood that the above disclosure has beenmade only by way of example as required by law and that many changes inthe details of construction and the combination and arrangement of partsmay be resorted to without departing from the spirit and scope of myinvention as hereinafter claimed.

What I claim is:

1. A hand operated switch comprising a base, a housing of insulatingmaterial attached to the base, having an outer wall, and side wallsextending therefrom toward the base; a plurality of parallel conductingpaths on the outside of the outer wall each comprising in series a firstterminal element, a current heated element of a thermal overload device,a pair of spaced stationary contacts, and a second terminal element; anda thermal overload device on the inside of the outer wall having aportion extending outwardly through the outer wall and heated by theheating element a mechanism frame secured to the base under the outerwall; a snap mechanism mounted on the mechanism frame and under theouter wall and enclosed by the side walls and comprising a snap elementreciprocable with snap movements; a reciprocator extending from the snapelement outwardly through a first aperture in the outer wall and betweenthe stationary contacts and carrying bridging contacts outwardly of thestationary contacts aligned therewith for mutual cooperation uponreciprocation of the snap element; the mechanism comprising a pair offiat sheet metal handle arms extending therefrom outwardly through apair of slots in the outer wall, and a handle between the arms outward-1y of the outer wall; the mechanism comprising means to effect said snapmovements of the snap element upon to-and-fro movement of the handlearms by the handle; pin means in the handle and slot means in the flatarms, attaching the handle to the arms and operable by manual shiftingof the pin for readily detaching the handle from the arms, angularlypositionable rotary means attaching the bridging contacts to thereciprocator and rotatable to a position for readily detaching thebridging contact from the reciprocator, and threaded means for readilyattaching the housing to the base and detaching it therefrom; wherebyupon detaching the handle and bridging contacts, and by virtue of saidapertures, the housing and the conducting paths and thermal devices andheating elements can be removed in unison from the base, leaving themechanism undisturbed thereon for inspection.

2. A switch as described in claim 1 and in which the current heatedelement is a coil on the outside of the outer wall; and the thermaldevice is mounted on the inside of the outer wall and has a heatableelement projecting through the outer wall into the coil; and the thermaldevice comprises a finger movable responsive to heating of the heatedelement by overload current in the conducting path; and the mechanism isactuated by movement of the finger to move the reciprocator with snapmovement in the direction to unbridge the stationary contacts.

3. A switch comprising a base, a housing of insulating material havingan outer wall spaced from the base; a switch operating mechanism betweenthe wall and the base, comprising a reciprocable element; a plurality ofpairs of spaced stationary contacts on the outside of the wall; areciprocator of insulating material connected to the reciprocableelement and reciprocable thereby and extending outwardly through anaperture on the housing wall between the pairs of stationary contacts,and carrying a corresponding plurality of bridging contacts outwardly ofthe stationary contacts, disposed to engage and disengage the pairs ofstationary contacts upon reciprocation of the reciprocator; the housingwall formed to provide a correspond plurality of pairs of walledchambers on opposite sides of the reciprocator and open toward thereciprocator; the reciprocator formed to provide a fourth wall for allthe pairs of chambers; whereby the engagement and disengagement of thecontacts occurs in the chambers.

4. A switch as described in claim 3 and in which the reciprocator isformed to provide also barrier walls between the bridging contactscarried thereby.

5. In a switch comprising a housing of insulating material and formed toprovide a plurality of pairs of walled chambers closed on three sidesand open towards its pair; a corresponding plurality of pairs ofstationary contacts supported in spaced relation onthe housing andhaving at least a portion of each disposed in one of the walledchambers; a reciprocator carrying a corresponding plurality of bridgingcontacts; operable means to reciprocator to cause all of the bridgingcontacts to bridge and unbridge the portions of respective pairs ofstationary contacts disposed in the walled chambers; the reciprocatorbeing of insulating material and formed to comprise a bar extendingbetween the open sides of all of the walled chambers; and having aportion formed for connection to the operable means.

6. A switch as described in claim 5 and in which the reciprocator bar isprovided with barrier walls between each of the bridging contactscarried thereby.

7. A switch as described in claim 5 and in which the reciprocator isformed to provide fourth wall for all of the pairs of walled chambers ofsubstantially the same height when the stationary contacts areunbridged.

8. A hand operated switch comprising movable and stationary contacts; amechanism operable to engage and disengage the contacts; a pair ofspaced handle arms for operating the mechanism; a handle between thearms; means for readily attaching the handle to the arms and detachingit therefrom, comprising hook portions on each arm at opposite sides ofthe handle provided by axially aligned circular perforations openinginto parallel slots; a round pin mounted on the handle for manual axialmovement thereon; the pin having a pair of longitudinally spaced largediameter portions to slidingly fit the arm perforations, and having apair of small diameter portions, both at the same longitudinal side ofthe large perforations and adjacent thereto and of a diameter slightlysmaller than the width of the slots; the pin being movable axially, andwhen in a first axial position, the large diameter portions of the pinprojecting through the arm perforations, thereby attaching the handle tothe arms; and when in a second axial position the small diameterportions being disposed opposite to the slots, whereby the pin andhandle may be detached from the arms by moving the handle to withdrawthe small diameter portions of the pin outwardly through and out of theslots; and means yieldably maintaining the pin in said first axialposition comprising a radially extending projection on the pin abuttinga portion of the handle, and a spring reacting between the handle andthe pin and yieldably maintaining the projection in said abuttingcondition.

9. A switch as described in claim 8 and in which, at least one of thearms has a finger which when the large diameter portions of the pin arein the arm perforations is disposed between inner and outer abutmentsprovided on the handle to prevent rocking of the handle on the pin, andwhich when the handle is moved to withdraw the small diameter pinportions out of the slots, the inner abutment is moved with the handleto a position that clears the finger and permits the handle and thesmall diameter portions of the pin to be removed outwardly away from thearms to detach the handle from the arms.

10, A switch as described in claim 8 and in which, the mechanism ismounted in a housing and is operated by to and fro movement of the arms,and the housing has a shoulder which is adjacent to the arms when theyhave been moved to operate the mechanism to disengage the contacts; andthe pin is rotatable in the handle; and the handle has a locking barconnected to the pin and disposed at one side of the handle; and thelocking bar has a portion normally projected into a recess in thehandle; and the said portion is removed from the recess in said secondaxial position of the pin, and the locking bar is then rotatable withthe pin to dispose a portion of the locking bar behind the projection toprevent movement of the handle and arms that operates the mechanism toengage the contact.

11. A hand operated switch comprising a frame supporting stationarycontacts; a reciprocator carrying movable contacts, normally disengagedfrom the stationary contacts; a snap mechanism for moving thereciprocator to engage the contacts with snap action, the snap mechanismcomprising; an elongated latch pivoted at an intermediate point on afirst pin stationary on the frame, and the latch at one side of thepivot normally latched against pivoting by a trip mechanism, andcarrying a fulcrum pin on the other side of its pivot; a reciprocatorpin on the reciprocator; a two'leg bell-crank connected at anintermediate point to the reciprocator pin, and one leg pivoted on asecond pin stationary on the frame, and the other leg carrying a bellcrank pin; a normally broken toggle comprising twolinks connectedtogether at one end by a toggle pin and at their other ends con nectedrespectively to the bell-crank pin and the fulcrum pin; a handle armpivoted at an intermediate point on the said second stationary pin andat one end provided with a handle and at the other end carrying an armpin; the toggle pin and arm pin disposed to have a center linetherebetween normally above the fulcrum pin; a tension 15 snap springconnecting the toggle pin and arm pin and acting along said line; thesnap spring force on the toggle pin being transmitted to the bell-crankpin through a said toggle link and tending to pivot the bell-crank onthe second stationary pin to thereby move the reciprocator pin andreciprocator in the contact disengaging di rection, and a first stoplimiting pivoting of the bell-crank, in that direction; the handle armbeing manually pivotable on the second stationary pin in a direction tocause the line of action of the snap spring to move below the fulcrumpin and substantially straighten out the toggle, and the toggle therebypivoting the bell-crank on the second stationary pin and moving thereciprocator pin and reciprocator in the direction to effect engagementof the contacts, and a second stop for limiting pivoting of thebell-crank in that direction.

12. A switch and snap mechanism as described in claim 11 and in whichthe normal pivoted position of the handle arm before snap action isdetermined by a portion of the latch beyond its fulcrum pin engaged bythe arm pin.

13. A switch and snap mechanism as described in claim 11 and in which,after snap action has occurred to engage the contacts, the handle arm ispivotable on the second stationary pin in the reverse direction, and thearm pin then causes the line of spring action to move above-the fulcrumpin; and the toggle is thereby again broken, and the bell crank isthereby pivoted back to its normal position, disengaging the contactswith snap action.

14. A switch as described in claim 11 and in which the handle arm has aportion adjacent to a portion of the toggle when the said line of actionis below the fulcrum pin, and which, when the handle is moved to causethe line of action to be above the fulcrum pin, will engage the saidportion of the toggle and initiate movement thereof in the collapsingdirection upon failure of the toggle to be so moved by the snap spring.

15. A switch and snap mechanism as described in claim 11 and in whichthe latching of the said end of the latch is effected by a notch in theend of the latch engaged with a portion of a trigger pivotally supportedon the frame and the trigger portion is held in engagement with thenotch by a trigger spring; and means is provided to pivot the triggeragainst the trigger spring force upon the occurrence of overload currentin the engaged contacts to release the latch notch; and the said snapspring acting through the toggle link that is between the toggle pin andfulcrum pin, pivots the latch on the first stationary pin and therebymoves the fulcrum pin below the line of action of the snap spring;whereupon the snap spring as aforesaid in such case moves thereciprocator to disengage the contacts with snap action.

16. A switch and snap mechanism as described in claim 15 and in whichthe pivoted trigger comprises an arm extending from the pivot, and themeans to pivot the trigger comprises a thermo-responsive device having afinger that is snap-moved upwardly from a normal position, by a devicespring upon occurrence of overload, and an intermediate element restsupon the finger between the finger and the trigger arm and is raised bythe finger and an upper portion of the intermediate element engages andpivots the trigger arm.

17. A switch and snap mechanism as described in claim 16 and in whichthe handle arm has a portion adjacent to an upper portion of theintermediate element; and after tripping on overload and disengaging ofthe contacts and raising of the intermediate element upward by thedevice finger, the handle arm is pivotable to cause said adjacentportion to engag'e said upper portion of the intermediate element andmove it, and the device finger on which it rests, downwardly, to resetthe device finger to normal position.

18. A switch comprising stationary contacts; reciprocably movablecontacts to engage and disengage the stationary contacts; a pivotedlatch carrying a fulcrum pin; a trigger and a thermo-responsive devicefor moving the trigger from a normal position upon occurrence ofoverload in the engaged contacts; the latch being latched againstpivoting by a portion of the trigger in its normal position; a snapmechanism connected to the movable contacts to reciprocate themcomprising a pivoted handle arm having a normal position and connectedto pivoted elements of the mechanism by a tension spring normally on aline of action at one side of the fulcrum, the elements reacting byspring tension upon the fulcrum and thereby normally holding the movablecontacts reciprocated to disengaged position; the line of action of thespring being shiftable to the other side of the latch carried fulcrumupon manual pivoting of the handle arm from its normal position in onedirection, the element then reacting by spring tension upon the fulcrumto cause the movable contacts to be moved to contact engaged positionwith snap action; the latch, upon being unlatched by the trigger when itis moved from normal position, being pivotable by the reaction of thespring to shift the latch carried fulcrum to a position at which theline of action of the spring is on the said one side of the fulcrum, tocause the elements to react by spring tension on the fulcrum and returnthe movable contacts to disengaged position.

19. A switch and mechanism as described in claim 18 and in which withthe contacts engaged, pivoting of the handle arm in the other directionshifts the line of action of the spring above the latch-carried fulcrumand the element react by spring pressure on the fulcrum to move themovable contacts to disengage position.

20. A switch and mechanism as described in claim 19 and in which afterunlatching of the latch by movement of the portion of the trigger fromits normal position, means is provided to effect restoring of thetrigger portion to normal position and to effect relatching of the latchthereon, operable by pivoting of the handle in the said other directionbeyond the position at which the movable contacts were moved todisengaged position.

21. A hand operated switch comprising a frame supporting stationarycontacts; a reciprocator carrying movable contacts, normally disengagedfrom the stationary contacts; a map mechanism for moving thereciprocator to engage the contacts, with snap action, the mechanismcomprising; an elongated latch pivoted at an intermediate point on afirst pin stationary on the frame, and the latch at one side of thepivot normally latched against pivoting by a trip mechanism, andcarrying a fulcrum pin on the other side of its pivot; a reciprocatorpin on the reciprocator; a first connecting element between thereciprocator pin and a second pin stationary on the frame; a secondconnecting element extending from the reciprocator pin and carrying aconnection pin; a normally broken toggle comprising two links connectedtogether at one end by a toggle pin and at their other ends connectedrespectively to the connection pin and the fulcrum pin: a handle armpivoted at an intermediate point on the second stationary pin and at anend provided with a handle and at the other end carrying an arm pin; thetoggle pin and arm pin disposed to have a center line therebetweennormally above the fulcrum pin, a tension snap spring connecting thetoggle pin and arm pin and acting along said line; the snap spring forceon the toggle pin being transmitted to the said connection pin through asaid toggle link and tending to pivot the first and second connectingelements and connection pin around the second stationary pin to therebymove the reciprocator pin and reciprocator in the contact disengagingdirection; and a first stop limiting movement of the reciprocator inthat direction; the handle arm being manually pivotable on the secondstationary pin in a direction to cause the line of action of the snapspring to move below the fulcrum pin and substantially straighten outthe toggle and the toggle thereby pivoting the connection pin andconnecting elements on the second stationary pin and moving thereciprocator pin and reciprocator in the direction to engage thecontacts, and a second stop limiting movement of the reciprocator inthat direction.

22. A switch as described in claim 11 and in which the handle arm has aportion adjacent to a portion of the toggle when the said line of actionis above the fulcrum pin, and which, when the handle arm is moved tocause the line or" action to be below the fulcrum pin, will engage thesaid portion of the toggle and initiate movement thereof in thestraightening out direction upon failure of the toggle to be so moved bythe snap spring.

23. A hand operated switch comprising stationary contacts, and movablecontacts movable to engage the contacts with snap movement by a snapmechanism; the snap mechanism comprising a pivoted handle element havinga handle at one side of the pivot and a toggle comprising two partspivotally connected at a toggle mid-point and the toggle having a normalbent condition and operable to go to substantially straightenedcondition, by an overcenter spring connected between a point on thehandle element on the other side of the handle pivot and the mid pointupon pivotal movement of the handle element in one direction;connections between the toggle element and the movable contacts, to snapthe latter to engaged position upon straightening out of the toggle; aportion of the handle element on said other side of the handle pivotcoming into engagement with an intermediate portion of the toggle toinitiate straightening out thereof by the handle element upon saidpivotal movement of the handle element upon failure of the over-centerspring to do so.

24. In a hand operated switch, a housing comprising a base portion and acover portion; movable and stationary contacts; a snap mechanism mountedon the base portion under the cover portion; a handle arm connected tothe mechanism extending outwardly through an aperture in the coverportion; a handle element on the outer end of the handle arm; the snapmechanism being operable to move the movable contacts to enage ordisengage the stationary contacts upon alternate movements of the handlearm in said aperture by said handle; a finger pivoted on the handle bypivot means providing for axial and rotary movement of the finger; aspring normally constraining the finger to move to one axial position,and in that position having a portion engaged with positioning means onthe handle preventing rotary movement of the finger; manually operablemeans to shift the finger in the other axial direction to permit manualrotation of the finger to a second position; the finger in said secondposition engageable with a shoulder on the housing cover portion andconstituting a stop preventing movement of the handle and handle arm.

25. A switch comprising three pairs of stationary contacts; areciprocator of insulating material carrying a bridging contact for eachpair of stationary contacts; a pivoted handle; a snap mechanism operableby pivoting movements of the handle in alternate directions to on andofl positions to elfect reciprocations of the reciprocator to bridge andunbridge the pairs of contacts; the mechanism comprising a pair oftriggers extending from a rotatably supported pin and spaced apart inparallel relation; three thermally activatable devices comprisingrespective fingers spaced apart in alignment; means giving snapmovements to the fingers respectively when the respective devices areactivated; a fiat thin bar of insulating material, the ends of the barprojecting through spaced apart stationary slots and the bar having noconnection with other parts and being free floating and slidable in theslots; the bar having spaced apart side edges; one edge having threerecesses embracing the three fingers respectively to position the barlongitudinally and laterally in a normal position; the other edge beingnormally adjacent to the said pair of triggers; the snap movement ofeither one or more of the fingers moving the bar in the slots androcking it around a finger not having made snap movement and causing itsother edge to move and engage and rotate the triggers; the mechanismcomprising means activated by the rotated triggers to eifectreciprocation of the reciprocator to unbridge the contacts; the handleupon pivoted movement in the off direction and somewhat beyond the 01fposition to a resetting position, engaging the said other edge of thebar and moving the bar to restore it to its normal position and to causeit to restore the snapped finger or fingers to normal unsnappedpositions; and means restoring the arm back to its ofi position afterresetting.

26. A hand operated switch comprising stationary contacts, and movablecontacts movable to enage and disengage the contacts With snap movementby a snap mechanism; the snap mechanism comprising a pivoted handleelement having a handle at one side of the pivot and a toggle comprisingtwo parts pivotally connected at a toggle mid-point and the toggleoperable between a collapsed condition and a substantially straightenedcondition; by an over-center spring connected between a point on thehandle element on the other side of the handle pivot and the togglemid-point connections between the toggle element and the movablecontacts, to snap the latter to disengage position upon collapse of thetoggle; and upon pivotal movement of the handle in one direction aportion of the handle element on said other side of the handle pivotcomes into engagement with an intermediate portion of the toggle toinitiate collapse thereof by the handle element upon failure of theover-center spring to do so.

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